Weighing scale



5. N. HURT WEIGHINGYSCALE Filed July 1, 1938 3 Sheets-Sheet l ATTORNEYSPatented July 16, 1940 UNITED STATES azcasss WEIGHING SCALE I Samuel N.Hurt, Toledo, Ohio, assignor toToledo Scale Company,

a corporation of New Jersey Application July 1, 1938, Serial No. 217,002

6 Claims.

This invention relates generally to weighing scales, and moreparticularly to weighing scales having means for automaticallyindicating the weight, such as, for example, a relatively movable chartand indicator.

The principal object of the invention resides in improved means fortransmitting motion to the movable member of the indicator couple.

Another object of the invention is the provision of improved flexiblemeans for actuating a scale indicator member.

Another object is the provision of improved flexible means which have nolost motion for driving an indicator in accordance with the displacementof the automatic counter-balancing system by the applied load.

Still another object is the provision of improved indicator drivingmeans whereby the movement of the indicating member may be greatlyamplified.

A still further object is the provision of improved means whereby thenormal amplitude of movement of the indicator may be maintained and theoscillating angle of the scale levers reduced; and,

A still further object is' the provision of an improved, flexible scaleindicator drive.

These, and other objects and advantages will be apparent from thefollowing description in which reference is had to the accompanyingdrawings, illustrating a preferred embodiment of the invention andwherein similar reference numerals refer to similar parts throughout theseveral views.

-In the drawings:

Fig. I is a perspective view of a scale of a type in which the inventionmay be embodied.

Fig. II is an enlarged, fragmentary view of the load counterbalancingand portions of the load indicating means.

Fig. III is an enlarged, fragmentary view taken substantially along theline IIIIII of Figure II.

Fig. IV is an enlarged, fragmentary sectional View of the motionmultiplying roller, the section being substantially along the line IV-IVof Figure II.

Fig. V is a sectional view through the pendulum substantially along theline V-V of Figure II.

Fig. VI is an enlarged, fragmentary view of one of the ends of thecompensating plate and showing in detail the pivotal connection with thependulums; and,

Fig. VII is a sectional view substantially along the line VII-VII ofFigure V.

Referring to the drawings in detail:

The scale in which the invention is shown embodied comprises a base i,which preferably is a rigid iron casting, housing the usual loadsupporting lever system (not shown).v In the well known 5 manner aplatform 2 is pivoted on the lever system. A deck portion 3, projectingoutwardly at the rear of the base i, supports a column 4. This column 4is hollow and in an enlarged portion near its upper end a beam lever 5is pivotally 10' mounted. Suitable projecting brackets secured to thelever 5 have bolted thereto beams 6 and l on which poises 8 and 9 areslidably mounted for the usual purpose. Connections (not shown)extending between the load supporting lever system in the base and thelever 5 are provided to transmit the pull resulting, from a load on theplatform to the load counter-balancing mechanism situated in asubstantially watchcase-shaped housing l0, surmounting and bolted to thecolumn 4. A rod l I, which forms the upper terminal member of theconnecting means, is secured, by means of nuts l3, to a stirrup l2 whichwith the aid of a V grooved bearing it engages a load pivot 15 in alever 16. This lever l8 is provided with a pivot ll extending throughone of its ends and which is fulcrumed on a bearing 8 suitably mountedin a bracket 19 bolted in proper position to the inner wall of thehousing it.

A power pivot 20 fixed in the opposite, free end of the lever it engagesa suitable bearing in a stirrup 2! suspended by means of a rod 22 from ayoke 23. This rod 22 projects through a bore in the yoke and isadjustably secured therein by means of nuts 24 one of which ispositioned above the yoke and the other below. Flaps of hinges 25 arefastened by means of screws 26 to outer parallel faces of the yoke 23and the other flaps of these hinges are fastened by means of rivets toshaped, upwardly extending arms 21. The upper ends of these arms 2i areclamped to the lower ends of flexible metallic ribbons 28 overlying andfastened to arcuate faces of power sectors 29 which are integralportions of rolling fulcra load, counterbalancing pendulums 30.

For the purpose of suspendingly supporting these pendulums 30 a pendulumfulcrum frame 3| is secured by bolts 32 and 3 to properly located bossesin the interior of the housing I {1. This. fulcrum frame 3i is providedwith parallel, machined track faces, and pendulum fulcrum ribbons 34 areclamped by means of clips 35 and screws 36 to the upper ends of thesefaces. These ribbons 34 overlie and are fastened to the lower 5 ends ofarcuate faces. of fulcrum sectors 31 by means of clips 38 and screws 39.To obtain greater accuracy and stability these fulcrum sectors 3'! ofeach pendulum are cast integral with extending transversely through thehub ill of v edges 48.

the power sector 29 and a hub 40.

For a purpose which will hereinafter be more fully described,a pivot barM is seatedin a bore each of the pendulums 38. Thisv bar is firmly fixedin position by means of 'a suitable retainer 42. The ends of this. bar 4I, which'project beyond the faces of the hub All, are milled to formknife. Studded into downwardly depending projections 43 of the hubs arependulum stems 44 onwhich pendulum weights 45 are adjustably threaded.Lock nuts 46, threaded on the stems M above and below the weights 45,are provided of the pendulums into rotary motion of an indi-' catorso-called compensating plates t"! operav tively engage the projectingknife edges. 48 by means of V grooved bearings 49; The compensatingplates ii are preferably constructed from thin, but stiifsheet steel andeach of the ends of these plates 47 is provided with a substantially. Dshaped aperture. To permit the bearings 61% tobe assembled in theaperture a narrow slot 51 extends between one side of the aperture andthe outer end of the bar and is so positioned in relation to thestraight side that a small shoulder remains which serves to retain the\i bearing 49 which is provided with a milled slot in. which thecompensating plates are seated. This slot extends'at right angles to theV groove of the bearing. Round holes in the compensating platespositioned substantially midway between the We of the bearings 59receive'cylindrical, trunnion-like ends 52 of a transversely positionedconnecting bar 53 having an otherwise square cross section. The extremeends of thesetrunnions, which project through the plates, are threadedandprovided with nuts. 54!. These nuts Ed prevent the compensatingplates d'l from spreading laterally and the bearings 49 are thusconstrained to maintain their positions on the pivots '48. Since thestraight side of the D shaped aperture 56 is slightly longer than thewidth of'the V bearing 49 these bearings may shift slightlylongitudinally on the plate 5?. to. accommodate themselves to slightvariations in. the distance between the knife edges 38 in the.

tipped slightly out of its level position. These.

variations are very small but unless compensation is provided frictionbetween the bearings and the pivots will result and cause inaccurateweighing results. Heretofore these compensating plates in scales of thetype described were operatively connected to the pendulums by means ofhorizontally extending cone pivots engaging apertures in the ends ofhardened members in the. pendulum hubs and'sincemeans were alsoprovidedfor the compensatingfor the variation in the pivot distance thatconstruction required a great deal of care in manufacture and they.

were correspondingly expensive. The' knife edge less to manufacture andis an improvement since there is less friction and less wear especiallywhen the scale is installed in a position where it is subjected tovibrations and rough'handling.

Since the faces of the power sectors 23 are eccentric to the pointsabout which the pendulums turn the distance between the faces of the twoopposed pendulums vary with each different position. For this reason thearms 2?, which are suitably formed to clearmechanism later to bedescribed, are secured to the yoke 23 by means of the hinges 25 so thatregardless of the position of the power sectors the arms 2? are capableof aligning themselves to the proper angle.

Extending through a drilled hole in the connecting bar 53 and lockedtherein by means of nuts 55 is a hook 5 5 which supports the upper endof a rectangularframe 51 which straddles a shaft 58 and a cylindricalmember mounted thereon. The lower end of this frame 51 has aperpendicularly disposed face to which the upper end of a flexiblemetallic ribbon til is clamped by means of a clip and screw ti. of thisribbon 6B overlies a periphery of a cylindrical shoulder 62 of acylindrical member 63 circumjacently mounted on ashaft 6 1-. The ends ofthis shaftare hardened and ground and are mounted in anti friction ballbearings 65; positioned in circular apertures in flange-like portions E5of the frame 3!. The cylindrical member 63 is provided with a secondcylindrical shoulder ET on its opposite end (Figures IIIand IV) and aflexible metallic ribbon 68 is fastened thereto and overlies itsperiphery, its lower end.

is provided with a reinforcing clip (is from which a rectangularcounterweight. ll, whose function will hereinafter be made clear, is.suspended by the cooperation of a hook it. studded therein.

The shaft 58, hereinbefore referred to, is

rotatably mounted in anti-friction ball bearings 1 12 fixed to sideflanges '53- of the frame 3!. One end of this shaft 58 extends beyondthe face of the ball bearing, a distance sufdcient so that an indicatorM may be clamped thereto byv a hub- !5. The endof the indicator isformed into an index point 16 and cooperates with a row of said indicial'l' printed on a dial-like chart 78 which ends clamped to thecylindrical members. just referred to in such a manner that they are ispirally wound and unwound in opposite directions when the scale is inoperation. It is essential that care is taken in the assembly of theseribbons so that they have equal tension on the cylindrical members andthat they wind and unwind without buckling or kinking.

When a load is placed on the platform 2 its pull is transmitted throughsuitable intermediate mechanism, and the connecting rod I l with itsstirrup l2, to the lever i6 and through it and the yoke 23, the hingedmembersQl-and the ribbons 28 to the power sectors 25 of the loadcounterbalancing pendulumssii. Their fulcrum sectors 31, in theknownmanner, roll upwardlyon the ribbons 3d, the pendulum weights 35' swingoutwardly until their weight moments counterbalance the weight moment ofthe'load on the platform. As the pendulums move upwardly-thecompensating plates 4.1,which with their bearings 49 rest on the pivotst8. partake. of this .move-- The other end ment and a pull is exertedthrough the frame 5'! on the ribbon 60. The end of this ribbon 60 ispulled upwardly, unwinding from the cylindrical shoulder 62 and turningthe cylindrical member 6-3 about its axis in an anticlockwise direction(see Fig. II). This turning movement winds up the lower end of thespirally wound ribbon 86 thus rotating the cylindrical member 59 and theshaft upon which it is mounted and since the indicator M- is clampedthereto it is rotated through an angle which is proportionate to theweight of the load on the platform and its index point It points to theproper indicium in the series I? on the chart 58.

When the load is removed from the platform the pull on the pendulumbecomes zero and these roll downwardly on their fulcrum sectors 3'!releasing the pull on the ribbon 80. The weight H, which is suspended bythe ribbon 68 from the periphery of the cylindrical shoulder 61 of themember 63, exerts a downwardly directed force and through the spirallywound ribbon I9 causes the indicator 14 to return to the zero indicium.Since the Weight H always exerts a constant force in one direction anypossible lost motion in the system is obviated.

It should now be apparent that an indicator driving mechanism whichembodies the invention is a desirable feature in scales of the typedescribed. These scales of the type described are built in variouscapacities, each capacity requiring individual pendulum weights and insome instances individual fulcrum and power sectors. When a drivingmechanism embodying the instant invention is used, by varying thediameters of the cylindrical shoulders and the diameter of thecylindrical members, the same pendulum weights, fulcrum and powersectors may be used for more than one capacity since a smaller angularmovement of the pendulum caused by a lighter load may be convenientlymultiplied by the cylindrical members and the flexible ribbons so thatthe indicator will make a complete revolution.

It is also desirable at times to multiply the indicator movement so thatit will make two or more revolutions for the scale capacity to increasethe distance between the weight graduations which are then shown on twoor more series of indicia on the chart.

The embodiment of the invention herein shown and described is to beregarded as illustrative only, and it is to be understood that theinvention is susceptible to variation, modification and change withinthe spirit and scope of the suboined claims.

Having described the invention, I claim:

1. In a device of the class described, in combination, weighingmechanism comprising load receiving means, load counterbalancingmechanism and load indicating means, said load counterbalancingmechanism including a pair of oppositely acting pendulums havingvertical reciprocating motion, compensating plates pivotally connectedto said pendulums and partaking of their vertical motion, saidindicating means comprising a plurality of rotatable cylindricalmembers, at least one of said plurality of cylindrical members havingportions of different diameters, a weight indicator fixedly secured tothe other of said cylindrical members, means including a metallic ribbonextending between said compensating plates and said cylindrical memberhaving said different diameter portions, other ribbons extending betweensaid last mentioned cylindrical member and said cylindrical memberhaving said indicator fixedly secured thereto and a counterweightsuspended from a portion of said cylindrical member having said portionsof different diameter by means of a flexible metallic ribbon.

2. In a device of the class described, in combination, weighingmechanism comprising load receiving means, load counterbalancingmechanism and load indicating means, said load counterbalancingmechanism including a pair of oppositely acting pendulums havingvertical reciprocating motion, compensating plates pivotally connectedto said pendulums and partaking of their vertical motion; saidindicating means comprising a plurality of pivotally mounted cylindricalmembers, a weight indicator fixedly secured to one of said cylindricalmembers, a plurality of flexible metallic ribbons extending between saidcompensating plates and said cylindrical member having said indicatorattached thereto, some of said plurality of metallic ribbons havingtheir opposite ends attached to each of said cylindrical members andadapted to be wound spirally thereon, another of said plurality offlexible members being operatively connected to said compensating platesand another ribbon being attached to that cylindrical member not havingsaid indicator fixedly secured thereto and to a freely suspendedcounterweight.

3. In a device of the class described, in combination, weighingmechanism comprising load receiving means, load counterbalancingmechanism and load indicating means, said load counterbalancingmechanism including a pair of oppositely acting pendulums havingvertical reciprocating motion, compensating plates pivotally connectedto said pendulums and partaking of their vertical motion; saidindicating means comprising a plurality of pivotally mounted cylindricalmembers, a weight indicator fixedly secured to one of said cylindricalmembers, a plurality of flexible metallic ribbons spirally wound onopposite sides of said cylindrical members and connecting meansincluding a frame extending betweeen one of said cylindrical members andsaid compensating bars.

4. In a device of the class described, in combination, weighingmechanism comprising load receiving means, load counterbalancingmechanism and load indicating means, said load counterbalancingmechanism including a pair of oppositely acting pendulums havingvertical reciprocating motion, compensating plates pivotally connectedto said pendulums and partaking of their vertical motion, saidindicating means comprising a plurality of pivotally mounted cylindricalmembers, a weight indicator fixedly secured to one of said cylindricalmembers and flexible means extending between said compensating platesand said cylindrical member having said indicator secured thereto forrotating said indicator.

5. In a weighing scale, in combination, load receiving means, loadcounterbalancing mechanism and load indicating means in cooperativerelation, said load counterbalancing mechanism comprising a pair ofparallelly mounted pendulums, each of said pendulums having an eccentricface, said indicating means including members stationed below thehorizontal plane in which said pendulums are fulcrumed and on verticalplanes between said arcuate faces, a connection between said loadreceiving means and said arcuate faces of said pendulums and saidconnection including bowed, hinged nonfiexible members formed to clearsaid members of said indicating means stationed below and between saidpendulums;

6. In a weighing scale, in combination, load receiving means, loadcounterbalancing mechanism and load indicating means, said loadcounterbalancing mechanism including a pair of flexibly suspendedoppositely acting pendulums havinga reciprocating vertical motion; eachof said pendulums having knife edges extending on their 0 centers ofrevolution and rigid compensating

